Long Answer Type(a) Mention the important features of the Neanderthal man.
(b) What are homologous organs? How do they help in providing evidence for organic evolution?
a. Describe the different types of vascular bundles.
b. Give three anatomical differences between a monocot root and a dicot root.
c. Explain the effect of light and temperature on photosynthesis.
(a) Explain the transpiration pull theory for ascent of sap.
(b) Explain the process of spermatogenesis in humans.
(c) Define the following:
(i) Placentation
(ii) Parthenocarpy
(iii) Diffusion
(a) Why are xylem and phloem classified as complex tissues? Describe the structure of phloem.
(b) Describe the ultra-structure of chloroplast.
(c) State three functions of the placenta.
(a) Describe the experiment performed by Griffith. What conclusions did he infer from his observations?
(b) What is artificial insemination? Mention two ways in which it is useful in breeding of dairy animals.
(c) What is single cell protein? Give its source and significance.
(a) How did Hershey and Chase prove that DNA is the genetic material?
(b) Give one main application of each of the following:
(i) MRI
(ii) Ultrasound
(iii) ECG
(c) Explain the role of stem cells in medical treatment.
(a) Write short notes on:
(i) Multiple Alleles
(ii) Artificial measures to control population
(b) What complications will arise if the blood of an Rh positive person is transfused to an Rh negative person and vice versa?
(c) State any three goals of the human genome project.
(a)
(i) Multiple Alleles:
Multiple alternatives of the same gene which influence the same character and produce different expressions in different individuals of a species or population/some genes have more than 2 allelic forms. These different forms of a single gene are referred to as multiple alleles., e.g. human blood groups
(ii) Artificial measures to control population:
• Mechanical methods like use of condoms, diaphragms
•Chemical – Spermicidal creams, jellies, foams
• Oral contraceptive pills
• IUCD like copper T, Lippes loop
•Surgical Methods – Tubectomy/ Vasectomy
b. When Rh positive blood is given to Rh negative:
Rh antigens induce the formation of Rh antibodies in recipient’s blood. Anti Rh antibodies react with donors Rh antigens and agglutinate the blood/ clumping. • Transfusion of Rh negative blood to Rh positive produces no complication as no antibodies are found in Rh positive persons/ No agglutination.
c.
(c) Human genome project: A research effort to map the entire genome by determining the sequence of nucleotides in the DNA of each of the 22+X and Y chromosome and to study the function of human genes.
Goals:
i. To sequence the entire genome that includes above 3 million base pairs
ii. To identify 20,000 to 25,000 genes in human DNA
iii. To obtain a physical map of human genome by cloning DNA into YACs and BACs and cosmids
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